Login required to started new threads

Login required to post replies

Doval non-round ring's
Quote | Reply
So these look similar to a osymetric ring, assymetrical shape but far more rounded. "Dual-ovals," and actually have ramps and pins. Made by some Korean Company. http://www.doval.me is their website, you can find them on eBay. Once again there is the question of do they work, how would the work any different then what's out there ect. Seem to be new versions of this springing up all over the place.


---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
I swear by Rotor's, both cranks and rings.

Team Zoot-Texas, and Pickle Juice
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
+1 for rotor q rings over these without even trying them simply based on rotor's adjustability and these having one setting.
Quote Reply
Re: Doval non-round ring's [triflorida] [ In reply to ]
Quote | Reply
I'm not saying they don't work, I like the theory behind them, it makes logical sense to me. The question is how to develop them perfectly. I think that designing them assymetrically makes sense as well, coming into and coming out of the dead spots you naturally have different force. And they don't have 1 setting they have 5 assuming you don't care where the chain pin sits.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Unless, I'm missing something in the picture you posted of the rings, they do not have 5 "settings" to fine-tune where the lobes are in the pedal cycle. Take a look at the Rotor rings, and you will see that the bolt holes are completely around the circle, thus allowing you to dial-in where the lobe of the ring sits in relation to the crank arm.
Essentially, as I recall (and my memory could be mistaken) the Osymmetrics and the old Bio-Pace rings only have 1 (fixed) position to dial-in the lobe with the crank arm.
joroshiba wrote:
I'm not saying they don't work, I like the theory behind them, it makes logical sense to me. The question is how to develop them perfectly. I think that designing them assymetrically makes sense as well, coming into and coming out of the dead spots you naturally have different force. And they don't have 1 setting they have 5 assuming you don't care where the chain pin sits.

Team Zoot-Texas, and Pickle Juice
Quote Reply
Re: Doval non-round ring's [Taugen] [ In reply to ]
Quote | Reply
If a position changes the angle with which you interact with the larger/smaller portions of the ring. I can put the crankarm in 5 positions on this ring where it will interact with the shape in distinct different ways in my pedal stroke.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
true, but MAYBE 2 of the 5 would make sense...
Quote Reply
Re: Doval non-round ring's [btmoney] [ In reply to ]
Quote | Reply
I can find 3 that you could justify one way or another. It certainly isn't as adjustable as the Rotor rings, but it will fit more cranksets because of that AND it is cheap! I just nabbed a set for $121 on eBay brand new. Yay Korea. I will have to test and see how it is.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Update: got these rings today. The ramps and pins are very solid and they actually shift better than my Rival chainrings ever have (better ramps and pins, stiffer rings). Overall machine work on them looks alright, some rough edges, certainly more material could have been removed from them. Setting up the front derailleur was a bit tricky but I've got it pretty well down now, rubs a bit in the 52-11 combo but barely. I'll fiddle with this some more later. I plan on doing some tests between these, my round rings and these in the "optimal position" as indicated by noncircularchainrings.be. Since I don't have a power meter I'm thinking of just doing a 10-20 min all out efforts on the trainer for each setup. I'll make sure I have an equal amount of rest going into each test. And hopefully I'll be able to do 2 rounds, 1 before adaptation and one after a couple weeks on them. I'm sure somebody has an idea of how to better this little bit of science, let me know if you do.

The major and minor axis seem to have quite an acute angle. Transitions from a 48 to a 55 with 52 teeth. Small chainring goes for 38 to 42 with 40t. Almost all the documentation that came with it is in Korean and thus totally meaningless to me. Although I did find a section with some wattages percentages and speeds mentioned. No idea what they mean though.

Anyways here is a pic mounted, those two lines in the upper left of the ring indicate largest and smallest diameter:


---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Hi joroshiba,

You can't test non-round rings well without the right inertia (rider+bike). They work by changing pedal speed against wheel speed, and with typical trainers wheel speed changes more instead.

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
Quote Reply
Re: Doval non-round ring's [damon_rinard] [ In reply to ]
Quote | Reply
damon_rinard wrote:
Hi joroshiba,


You can't test non-round rings well without the right inertia (rider+bike). They work by changing pedal speed against wheel speed, and with typical trainers wheel speed changes more instead.

Cheers,

Thanks Damon, this makes sense. However, would this not also mean that this rings do not work on a steep climb? Where wheel speed and pedal speed are going to be more closely related. I wouldn't say with a typical trainer wheels speed changes more than pedal speed (this would imply that when I gradually decrease pedal speed, the wheel would stop before I stop pedaling when we know there will in fact be a couple of seconds after I stop pedalling that the wheel keep spinning), but that wheel speed changes quicker than on a flat road. Thus this perhaps wouldn't be the ideal test for non-round rings, but it would be a similar scenerio to a mountain climb where there is less inertia. Would you consider this to be accurate?

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Hi joroshiba,

No.

I haven't thought it too much because the inertia is so different on a trainer I can't imagine there is any scenario where testing non-round rings on a trainer is worth it.

An intentionally high-inertia ergometer on the other hand...

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
Quote Reply
Re: Doval non-round ring's [damon_rinard] [ In reply to ]
Quote | Reply
Fair enough. I will likely continue with the test, with the caveat that if I find no improvement it doesn't necessarily mean there isn't one. But it would seem as though if I get an advantage in a scenerio with such a low interia you would simply expect bigger advantages on the road. If there were any mountains near by I would do a test there, but alas the longest climb within a 30 minute drive takes about 3.5 minutes to go up. I might still test here, but I doubt I will find significant enough differences to say that it wasn't simply that I was able to push myself harder on a given day that improved my time up. I could do repeats though, this could test the theory that they reduce fatigue.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
I was getting fitted on my new tri bike the other day which has some osy rings on there. The fitter kept looking bewildered as I was peddling and I asked him what was going on. He said that my foot came across the top so fast that it really just took him a while to get used to that rythym of the feet. He said it looked like they were doing what they were supposed - allowing the foot to come through the dead spot faster...take that for what it is worth
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
 
Am I missing something here? Wouldn't this resistance slope need to start and end in the same place since 6 o'clock on one leg is 12 o'clock on the other?



Quote Reply
Re: Doval non-round ring's [bnation] [ In reply to ]
Quote | Reply
I noticed the same thing, I don't have any idea how they managed to find that. I will say that there is a very sharp transition when going into the dead spot and a gradual increase afterwords maybe they just left a couple degrees off the chart?

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Since I don't have a power meter I'm thinking of just doing a 10-20 min all out efforts on the trainer for each setup. I'll make sure I have an equal amount of rest going into each test.

You really need to use a Powertap, and do many tests on the road. Even then it will be difficult to tell.



Quote Reply
Re: Doval non-round ring's [bnation] [ In reply to ]
Quote | Reply
Am I missing something here? Wouldn't this resistance slope need to start and end in the same place since 6 o'clock on one leg is 12 o'clock on the other?

Yes, but 6 on one leg will not be the same as 12 on the other. Each leg will have its own graph with this shape. The graph only shows half of the full circle.

Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
 
The more I think about that graph the more I think it was created by their marketing dept. If the y axis on that graph is resistance, the circular chain ring should be a flat line with the other rings going above the line during the downstroke and below during the deadspot, but averaging the same value.
Quote Reply
Post deleted by joroshiba [ In reply to ]
Re: Doval non-round ring's [bnation] [ In reply to ]
Quote | Reply
I would agree with this it looks like it is trying to represent what the resistance feels like.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [bnation] [ In reply to ]
Quote | Reply
If you really want a good laugh watch their videos. Poor grasp on the English language + metal music = world class marketing. Fortunately the product is of higher quality than these materials. At least from a shifting and build quality perspective. As far as them working goes.... I certainly hope so but who really knows?

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
The reason q-rings are a killer app pretty much in comparison to any other non-round rings: it is not their shape. It is their angular adjustability.

Because you absolutely need to be able to adjust the chainring position to fine tune its position relative to your body position, your saddle position, your specific frame geometry, and even your cassette size. A non-round ring without the ability to adjust ring position is dead in the water.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
A non-round ring without the ability to adjust ring position is dead in the water.

Osymetrics have been used very successfully by pros lately... I wouldn't call that "dead in the water".

Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
I would argue that you still might see some benefit in a chainring not in its optimal position. The ovality of qrings is so small that the magnitude of optimized gains will be too small. With a more eccentric shape you could have it not be position optimized and still get better results. Assuming the idea works in the first place.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [rruff] [ In reply to ]
Quote | Reply
rruff wrote:
Osymetrics have been used very successfully by pros lately... I wouldn't call that "dead in the water".


If osymetrics work, they would work far, far better for way more athletes if they had angular adjustment capability. A fixed ring forces you to take a gamble that the design will work ok with your set up. Kind of an iffy gamble.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
You are basing this on the assumption that the angle is critical. That may not be the case. It's quite possible that "getting close" is good enough, and that the rider can easily adapt to it.

Or it is possible that none of them really do anything to increase power...
Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
If you actually read the noncircularchainring.be study on different shapes and angles you will find that based on their models there are a wide variety of angles that work quite well (interestingly enough the recommended by Rotor seems to be terrible). Yes this is for one position but, shifting your seat angle likely won't move outside of the range of angles which improve pedaling power. Below is a summary of information (all percents are in comparison to circular ring with Osymmetric ring):
  • at 110 degrees to major axis: -7.9% peak force from the knee extensor, +15% from Hip Extensor and a +2.4% power increase {they consider optimal range based on power increase and knee force decrease}
  • 117 degrees: -7.5%, +16.2%, +2.5% {they consider optimal range based on power increase and knee force decrease}
  • 78 degrees (similar to standard mount for qring and osymmetric) : -1.5%,+4.6%, -0.7%
  • 125 degrees: -6.5%, +15.4%, +2.9%,
  • 128 degrees: -4.9%, +14%, +2.9%
  • 132 degrees: -3.2%, +18%, +2.7%

As you can see there are at least 20 degrees in which you get a measurable improvement, the study didn't include any other data points in the document which I find interesting, but the point here is that you can at least get in this range of improvement on the rings, likely regardless of your seat angle.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [rruff] [ In reply to ]
Quote | Reply
rruff wrote:
You are basing this on the assumption that the angle is critical. That may not be the case. It's quite possible that "getting close" is good enough, and that the rider can easily adapt to it.

No, I wouldn't say the angle is "critical", but in my personal experience it is very important if you want to really find that sweet spot where these chainrings really shine.

And that non-round chainrings' optimal positions are affected by way more things than just seat angle. For example, the best ring position is highly affected by seemingly random things like BB height, chainstay length, gearing choices, cog size, etc.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Thats an interesting study, but I'm not sure how much I trust it. It has the old Biopace chainrings being better than any of the current chainrings in their stock configuration. They only test the rings with a mathematical model though, and I wonder how much that actually reflects real usage.
Quote Reply
Re: Doval non-round ring's [bnation] [ In reply to ]
Quote | Reply
My understanding of Biopace rings is that they did have some small improvements till your knee blew up.It would be interesting to see the point at which they modeled no improvement and decreasing improvement for shape.

As for application to the real world: I know approximately nothing about bio-mechanics and feel unqualified to make any judgement on this. I know that the guys who put together the model know more about this then I do and have yet to hear anyone else who actually knows about this stuff either point out its flaws or endorse it. There for I trust it with some reservations.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
I guess you guys haven't heard about our QXL Rings :-)


Kervin

Rotor Bike Components USA
OUR NEW WEBSITE http://www.rotorbikeusa.com
Quote Reply
Re: Doval non-round ring's [damon_rinard] [ In reply to ]
Quote | Reply
damon_rinard wrote:
Hi joroshiba,

You can't test non-round rings well without the right inertia (rider+bike). They work by changing pedal speed against wheel speed, and with typical trainers wheel speed changes more instead.

Cheers,

I've found that a LeMond Revolution trainer has enough inertia to observe the "non-round ring on an SRM/Quarq inflation factor" ;-)

The "inflation factor" is also readily apparent riding outside with a PT wheel to compare it to...

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:
If you actually read the noncircularchainring.be study on different shapes and angles you will find that based on their models there are a wide variety of angles that work quite well (interestingly enough the recommended by Rotor seems to be terrible). Yes this is for one position but, shifting your seat angle likely won't move outside of the range of angles which improve pedaling power. Below is a summary of information (all percents are in comparison to circular ring with Osymmetric ring):
  • at 110 degrees to major axis: -7.9% peak force from the knee extensor, +15% from Hip Extensor and a +2.4% power increase {they consider optimal range based on power increase and knee force decrease}
  • 117 degrees: -7.5%, +16.2%, +2.5% {they consider optimal range based on power increase and knee force decrease}
  • 78 degrees (similar to standard mount for qring and osymmetric) : -1.5%,+4.6%, -0.7%
  • 125 degrees: -6.5%, +15.4%, +2.9%,
  • 128 degrees: -4.9%, +14%, +2.9%
  • 132 degrees: -3.2%, +18%, +2.7%

As you can see there are at least 20 degrees in which you get a measurable improvement, the study didn't include any other data points in the document which I find interesting, but the point here is that you can at least get in this range of improvement on the rings, likely regardless of your seat angle.

I've looked at those studies a bunch and it's not clear to me that the joint torques calculated by that model are correct since it appears that the model only considers a single leg...i.e. it doesn't take into account the fact that pedaling is done with a system of 2 legs coupled by the cranks.

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Quote:
I've looked at those studies a bunch and it's not clear to me that the joint torques calculated by that model are correct since it appears that the model only considers a single leg...i.e. it doesn't take into account the fact that pedaling is done with a system of 2 legs coupled by the cranks.
You would know better than me! I think it is still be worth testing, at least once though.

Quote:
I've found that a LeMond Revolution trainer has enough inertia to observe the "non-round ring on an SRM/Quarq inflation factor" ;-)

The "inflation factor" is also readily apparent riding outside with a PT wheel to compare it to...

Unfortunately I have no access to either of these. Sounds like I have no accurate means of testing. So instead I'll have to rely on my gut combined with less than ideal testing. If you have any ideas for semi-accurate methods, given the following long list of things I don't have access to that would be great: velodrome, hills longer than 3 minutes to climb (which really sucks since I excel at climbing), powertap (or power meter for that matter), lemond revolution. I do have a trainer, rollers with a resistance unit, and might be able to get access to a computrainer. Might have been easier to list things I do have access to haha.

I know you had done testing with osymetric rings to show the inflation factor, have you done any testing to see if they actually work as advertised beyond that?

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [kervinq] [ In reply to ]
Quote | Reply
kervinq wrote:
I guess you guys haven't heard about our QXL Rings :-)

Kervin, I have heard about them. Last I checked they weren't available yet (or officially announced), but they certainly solve the aforementioned small eccentricity. But have a few issues with buying them: a) both rotor and osymetric rings are simply out of my price range b)I think an asymmetric shape intuitively makes sense if there are actual gains to be had by changing shapes of he rings, simply put the forces when entering the dead spot or much different than those when exiting. It could turn out that this doesn't make many or any gains but I simply don't know, much like I don't really know if the concept at all works. So I simply follow my gut feeling and own (quite possibly flawed) logic, as well as the entirely unscientific experiences of others.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:

I know you had done testing with osymetric rings to show the inflation factor, have you done any testing to see if they actually work as advertised beyond that?


http://forum.slowtwitch.com/...rch_string=;#4274299

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [damon_rinard] [ In reply to ]
Quote | Reply
damon_rinard wrote:
Hi joroshiba,

You can't test non-round rings well without the right inertia (rider+bike). They work by changing pedal speed against wheel speed, and with typical trainers wheel speed changes more instead.

Cheers,

Interesting...especially since the O'Hara study that's shown prominently on the Rotor site was done using a Computrainer, no? Those don't have a very big flywheel IIRC...in fact, don't you remember ST'er "jens" having a custom 16 lb. flywheel machined for his Computrainer? ;-)

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
DarkSpeedWorks. Yes Indeed... rings would be much better served with multiple mounting positions.

Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
Something you made?



Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook
Quote Reply
Re: Doval non-round ring's [Ex-cyclist] [ In reply to ]
Quote | Reply
Yeah been tinkering with some stuff for a while. This version was hot out the CNC yesterday, first test ride today, sifting to the roadie tomorrow for a few power tests. Shifting is a little twitchie.....:)
Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
Let us know how it goes...



Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook
Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
Mrcooper wrote:
Yeah been tinkering with some stuff for a while. This version was hot out the CNC yesterday, first test ride today, sifting to the roadie tomorrow for a few power tests. Shifting is a little twitchie.....:)

Awesome work there, be intersted to see what you find. One of the things that is rather nice about these rings is they have very well shaped ramps and pins. Like I said before shift quality is better than it was with the Rival rings (which are crazy flexy). See picture below.


Took them out for their first longer ride today, felt wierd at first but by the end of 3 hours I didn't notice the difference at all. I did notice slightly different muscular use on the ride: more hamstrings, more glutes, seemed to work the quads the same (based on my fatigue level at then end of the ride). As for whether or not they work? Still no method to test that but I do know I'm certainly getting maximum placebo effect: I did the same route as I did last week at 1mph faster today, with less fatigue afterwords and winds were stronger today. But once again this proves nothing, so I'm going completely non-scientifically just believe they work and keep riding them.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
Are your rings Farther, Faster, More Interesting? http://www.youtube.com/...ed&v=fXHa6pcYwPg

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
Mrcooper wrote:
Yes Indeed... rings would be much better served with multiple mounting positions.

Did you CNC the entire ring, or did you just add the extra holes to an off-the-shelf oval ring? Either way, that's some impressive work.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:
I would argue that you still might see some benefit in a chainring not in its optimal position. The ovality of qrings is so small that the magnitude of optimized gains will be too small. With a more eccentric shape you could have it not be position optimized and still get better results. Assuming the idea works in the first place.

Ding, ding, ding...

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
joroshiba wrote:
I would argue that you still might see some benefit in a chainring not in its optimal position. The ovality of qrings is so small that the magnitude of optimized gains will be too small. With a more eccentric shape you could have it not be position optimized and still get better results. Assuming the idea works in the first place.


Ding, ding, ding...

The great thing here is that as long as they don't actually hurt my power output, and I believe that they work then they will work to some extent. I've also heard many argue that they have no power benefits but fatigue benifits once again.... no data. I choose to believe and therefore they work. Placebo effects are fantastic.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Last edited by: joroshiba: Nov 12, 12 14:09
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:
Tom A. wrote:
joroshiba wrote:
I would argue that you still might see some benefit in a chainring not in its optimal position. The ovality of qrings is so small that the magnitude of optimized gains will be too small. With a more eccentric shape you could have it not be position optimized and still get better results. Assuming the idea works in the first place.


Ding, ding, ding...

The great thing here is that as long as they don't actually hurt my power output, and I believe that they work then they will work to some extent. I've also heard many argue that they have no power benefits but fatigue benifits once again.... no data. I choose to believe and therefore they work. Placebo affects are fantastic.

If placebo didn't work, they wouldn't have to control for it in studies, right? :-)

It's funny...the guy who I'm borrowing the Osymetric ring from told me straight out that he doesn't care if it inflates the power on his Quarq and/or if it actually helps his power...he's sticking with them just because he likes how they feel.

Whatever floats your boat, I guess... ;-)

Depending on how things work with my experiment with them on the TT rig, I may end up using them there for the same reason. However, that then brings in the difficulty of having the inflated power values...unless I go back to running my PT wheel with a cover again. But, I'm also going to compare the effects the Osy ring in the "optimum" position vs. shorter cranks on a "feel" basis. My suspicion is that the "feel" will be similar.

Whatever floats your boat though, I guess... ;-)

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
When you say "Optimal" do you mean rotated 4 clockwise? This will get you close to the theoretical optimal for a road bike setup, but 10-12 degrees off for a tri bike angle. Trying a run with the mod setup I have to dial it in a little closer tonight. Will update if people are interested. Not sure I"ll have time to fit the large flywheel on the test set-up, but I'll run a round and osymetric original position along with the modified position. Might start a new thread since this is outside the DOVAL spectrum.
Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
Mrcooper wrote:
When you say "Optimal" do you mean rotated 4 clockwise? This will get you close to the theoretical optimal for a road bike setup, but 10-12 degrees off for a tri bike angle.

I think of it as "rotated 180 degrees and then back 36 degrees to line up with the arm" ...I'm not sure if that's the same as "rotated 4 clockwise" or not ;-)

IIRC, The major axis of the Osymetric ring was at 78 degrees from the pedal in the "stock" position. Effectively "retarding" that position by 36 degrees puts it at 114 degrees off of the crank arm, or only 3 degrees off of their calculated optimum for the major axis. Judging by the fact that there was only a difference of 0.1% between their predicted "power gain" at 110 degrees vs. 117 degrees, I'm thinking 114 isn't going to be somewhere in between. I also recall them saying that anything in the range of 110-120 degrees was in the "sweet spot" for positioning, no?

Hmmm..."10-20 degrees off for a tri bike angle"? Well, based on the above, plus the fact that I don't think I sit effectively 10-20 degrees different than my road position, I'm not sure how you're arriving at that conclusion.

BTW, my perception using that ring position on the road bike is that it would feel better if I was sitting further forward (i.e. really deep in the drops, or in my TT position). The pedal "drops away" really fast when using it and riding on the tops of a road bar...

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
If placebo didn't work, they wouldn't have to control for it in studies, right? :-)

It's funny...the guy who I'm borrowing the Osymetric ring from told me straight out that he doesn't care if it inflates the power on his Quarq and/or if it actually helps his power...he's sticking with them just because he likes how they feel.
I only notice a real difference in feel when climbing out of the saddle. Other than that it feels quite normal. Except for muscle use which I noticably used my hamstrings and glutes more. For now I'm sticking with them because my Rival rings suck (don't shift) and I paid money for these :P. When I do purchase my Quarq (which this molasses rate of saving will be around January) I may have to re-evaluate or I can just remember to take 4% off my power numbers when comparing to others or I could intimidate the competition.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:
Tom A. wrote:

If placebo didn't work, they wouldn't have to control for it in studies, right? :-)

It's funny...the guy who I'm borrowing the Osymetric ring from told me straight out that he doesn't care if it inflates the power on his Quarq and/or if it actually helps his power...he's sticking with them just because he likes how they feel.

I only notice a real difference in feel when climbing out of the saddle. Other than that it feels quite normal. Except for muscle use which I noticably used my hamstrings and glutes more. For now I'm sticking with them because my Rival rings suck (don't shift) and I paid money for these :P. When I do purchase my Quarq (which this molasses rate of saving will be around January) I may have to re-evaluate or I can just remember to take 4% off my power numbers when comparing to others or I could intimidate the competition.

Or, just buy a powertap...

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
Or, just buy a powertap...
I would if I didn't have training wheels + 2.5 wheelsets I use for different events. ( 303s for mountains, old HED wheels for everything else, and then my old Disc for TT's, paid a grand total of $100 for all of those wheels).

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Depending on how things work with my experiment with them on the TT rig, I may end up using them there for the same reason. However, that then brings in the difficulty of having the inflated power values...unless I go back to running my PT wheel with a cover again. But, I'm also going to compare the effects the Osy ring in the "optimum" position vs. shorter cranks on a "feel" basis. My suspicion is that the "feel" will

Tom if you plan to use them for TT's and round rings for the road bike won't you constantly be working against the muscular adaptation developed on the Osymetric rings? It took me a couple of weeks to feel completely comfortable "adapted" to the Osymetric rings on my TT bike. Consequently I switched to Osymetric rings on the road bike as well to keep from "readapting" to round rings.
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom

Could you speculate why the quark values are inflated?

What do you think is going on?

My understanding is that power is power, wondering your thoughts, why do you think the values split?
Quote Reply
Re: Doval non-round ring's [valdlaw] [ In reply to ]
Quote | Reply
valdlaw wrote:
Tom if you plan to use them for TT's and round rings for the road bike won't you constantly be working against the muscular adaptation developed on the Osymetric rings? It took me a couple of weeks to feel completely comfortable "adapted" to the Osymetric rings on my TT bike. Consequently I switched to Osymetric rings on the road bike as well to keep from "readapting" to round rings.

In a word...no. I actually found when riding the Osymetric big ring combined with a round small ring that it only took a minute or two of riding to "get used" to the different feel when going from one ring to the other...the funny thing being that it didn't matter if I was going round -> non-round, or non-round -> to round, after the transition my pedaling felt "jerky". That shows me that (at least for me) any "adaptation" occurs fairly quickly.

BTW, after talking a bit about this subject with a guy much smarter than me (Hi Jim!) there's something about that "adaptation" thing which would tend to imply that non-round rings won't really "work". Here's why: the use of non-round rings is built on the assumption that one can change the joint angle velocities (and thus muscle shortening speeds) in the upper portions of the leg (i.e. the hip and knee joints) as compared to when the legs are attached to a crank with round rings. The "problem" is though, that there are redundant degrees of freedom in the leg structure (i.e. the ankle joint..and even foot flexure) that may prevent this. Here's the kicker though...one can potentially vary those joint angle velocities around the pedal stroke by a much greater margin than any non-round ring could accomplish, just by changing ankle flexure.

The body is an amazing thing...and typically "left to it's own devices" will find the preferred joint angular velocities and muscle shortening speeds. So, what may actually be happening during those "adaptation" phases is your body re-learning how to pedal so that your preferred joint velocities are accomplished. Make sense? This is most likely the reason why, despite some analytical findings to the contrary, little to no power change between round and non-round rings is found through the vast majority of the scientific literature.

So...to get back to your question...I'm not that worried about having different rings on the road bike and TT bike, since my only reason for thinking they may "feel" better for me on the TT bike is probably more of a fit question, and something that I may be able to accomplish anyway with some shorter cranks I have coming my soon ;-)

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
It doesn't take me any time to adapt to mine I just get on and off go. I feels different for only as long as I think about it. I am switching between a fixed gear and these quite frequently right now and if anything the Doval rings feel smoother to me.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
valdlaw wrote:

Tom if you plan to use them for TT's and round rings for the road bike won't you constantly be working against the muscular adaptation developed on the Osymetric rings? It took me a couple of weeks to feel completely comfortable "adapted" to the Osymetric rings on my TT bike. Consequently I switched to Osymetric rings on the road bike as well to keep from "readapting" to round rings.


In a word...no. I actually found when riding the Osymetric big ring combined with a round small ring that it only took a minute or two of riding to "get used" to the different feel when going from one ring to the other...the funny thing being that it didn't matter if I was going round -> non-round, or non-round -> to round, after the transition my pedaling felt "jerky". That shows me that (at least for me) any "adaptation" occurs fairly quickly.

BTW, after talking a bit about this subject with a guy much smarter than me (Hi Jim!) there's something about that "adaptation" thing which would tend to imply that non-round rings won't really "work". Here's why: the use of non-round rings is built on the assumption that one can change the joint angle velocities (and thus muscle shortening speeds) in the upper portions of the leg (i.e. the hip and knee joints) as compared to when the legs are attached to a crank with round rings. The "problem" is though, that there are redundant degrees of freedom in the leg structure (i.e. the ankle joint..and even foot flexure) that may prevent this. Here's the kicker though...one can potentially vary those joint angle velocities around the pedal stroke by a much greater margin than any non-round ring could accomplish, just by changing ankle flexure.

The body is an amazing thing...and typically "left to it's own devices" will find the preferred joint angular velocities and muscle shortening speeds. So, what may actually be happening during those "adaptation" phases is your body re-learning how to pedal so that your preferred joint velocities are accomplished. Make sense? This is most likely the reason why, despite some analytical findings to the contrary, little to no power change between round and non-round rings is found through the vast majority of the scientific literature.

So...to get back to your question...I'm not that worried about having different rings on the road bike and TT bike, since my only reason for thinking they may "feel" better for me on the TT bike is probably more of a fit question, and something that I may be able to accomplish anyway with some shorter cranks I have coming my soon ;-)

Interesting. In my case I definitely felt that I was working different parts of my muscles and was sore for at least a week after I started the rings. So is the jury still out for you whether you plan to use the rings? Have you come to a definitive conclusion?
Quote Reply
Re: Doval non-round ring's [mauricemaher] [ In reply to ]
Quote | Reply
mauricemaher wrote:
Tom

Could you speculate why the quark values are inflated?

What do you think is going on?

My understanding is that power is power, wondering your thoughts, why do you think the values split?

No speculation necessary, just simple physics. Quarq (and SRM) power meters only calculate crank rotational velocity once per revolution, and the assumption made is that the rotational velocity is constant within a pedal revolution. This assumption works really well for the vast majority of situations on a bike and with round rings due to the high inertial mass of a bike+rider system.

However, non-round rings are designed to "work" by VARYING the crank rotational velocity and slowing down the crank during the highest torque phases of the pedal stroke. But, since Power is the product of torque x angular velocity, because the angular velocity during the high torque phases is naturally LESS than the average angular velocity assumed by the PM, this means that when summed over a single pedal revolution, the power will naturally be over-reported (even though the velocity is faster than average during other portions of the pedal cycle, the torques are significantly lower during those periods and thus the power doesn't "even out"). Dan Connelly covered this a bit more mathematically here: http://djconnel.blogspot.com/...uniform-cadence.html

The possibility of this "inflation" was speculated about first using simple math and physics. My testing was just to confirm those calculations...and it did.

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [valdlaw] [ In reply to ]
Quote | Reply
valdlaw wrote:
So is the jury still out for you whether you plan to use the rings? Have you come to a definitive conclusion?

Well...let's just say that knowing what I know now, I'm not expecting any magical power increases from them ;-)

And, if I can get the same "feel" I'm looking for on a TT bike with a shorter crank arm, I know which way I'll be going (and it most likely won't involve buying over-priced chainrings)...

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
valdlaw wrote:
So is the jury still out for you whether you plan to use the rings? Have you come to a definitive conclusion?


Well...let's just say that knowing what I know now, I'm not expecting any magical power increases from them ;-)

And, if I can get the same "feel" I'm looking for on a TT bike with a shorter crank arm, I know which way I'll be going (and it most likely won't involve buying over-priced chainrings)...

Ahh... so there is something you like about the "feel" of the chainrings? ;)
Please let us know what you determine I'm very curious to see where you land on this. For me I'm planning to go back to round rings for a couple of weeks to see how that "feels".
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A wrote:
The body is an amazing thing...and typically "left to it's own devices" will find the preferred joint angular velocities and muscle shortening speeds. So, what may actually be happening during those "adaptation" phases is your body re-learning how to pedal so that your preferred joint velocities are accomplished. Make sense? This is most likely the reason why, despite some analytical findings to the contrary, little to no power change between round and non-round rings is found through the vast majority of the scientific literature.

To expand on the concept above...I was told that there was a test done that showed no change in knee or hip flexure angles for a 6cm reduction in seat height.

That indicates 2 things to me: First, the body "desires" to operate in a particular condition, and if it can it will do so...and secondly, there's a lot of "slop" that can be taken up with the ankle joint!

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [valdlaw] [ In reply to ]
Quote | Reply
valdlaw wrote:

Ahh... so there is something you like about the "feel" of the chainrings? ;)

Only in that with the Osymetric ring in the speculated "optimum" position (i.e. major axis retarded w.r.t. the pedal by 36 degrees) I tended to like the "feel" of the harder resistance "coming on later" in the downstroke...or, with my leg further extended...when in an aero position.

Which is why I said I think I could probably get the same "feel" from just using shorter cranks ;-)

That's it really...I actually DID NOT like the feel of the Osymetric ring when riding in a bunch at speed...just felt too "jerky" without going up a gear, at which point it made it harder to accelerate to match surges.

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Another observation. My cadence is much lower with these chainrings, when I'm really mashing a big gear it feels smooth and doesn't feel like I'm going to rip off my knees like it normally does. I usually run a pretty high cadence averaging about 90-95 rpms with a mode of 99. On today's 4.5 hour ride I averaged 84 with a mode of 87. Unless I am mistaken... this could be an advantage as slower cadence utilize more slow twitch fibers which would mean that I'm not fatiguing as much over the course of the ride at a naturally selected cadence.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:
Another observation. My cadence is much lower with these chainrings, when I'm really mashing a big gear it feels smooth and doesn't feel like I'm going to rip off my knees like it normally does. I usually run a pretty high cadence averaging about 90-95 rpms with a mode of 99. On today's 4.5 hour ride I averaged 84 with a mode of 87. Unless I am mistaken... this could be an advantage as slower cadence utilize more slow twitch fibers which would mean that I'm not fatiguing as much over the course of the ride at a naturally selected cadence.

IIRC, fiber type utilization is basically driven by force level with ST fibers recruited first, followed by FT as the force level rises...so, for the same power but grinding at a lower cadence, you're actually going to be recruiting more fast-twitch fibers than you would be otherwise since the average pedal force would need to rise to keep the power constant. Maximum muscle shortening speeds of both types of fibers are way faster than either of those cadences anyway...

In any case, I put the Osymetric ring on my S5 today with it in the Belgian study determined "optimum" position (i.e. retarded by 36 deg from stock). It felt pretty good, and after just a minute or two my legs accommodated and the pedal stroke was fairly smooth.

Then, I went back to my garage and immediately put on a set of 165mm cranks (my normal length is 170mm) with round rings, and raised my saddle and bars by 5mm and moved the saddle/bars back 5mm so that the relationship between my foot in the powerstroke and the other touchpoints was held consistent. I then went out and tried it.

Guess what? As I suspected, the "feel" was almost identical...FWIW...

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
When I'm back at a computer I will look up the studies I had seen which led me to believe otherwise because what you stated was my understanding for a long time as well.

Doval chainrings are cheaper than a new crank set. Or most other chainrings that actually shift for that matter

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:
When I'm back at a computer I will look up the studies I had seen which led me to believe otherwise because what you stated was my understanding for a long time as well.

Doval chainrings are cheaper than a new crank set. Or most other chainrings that actually shift for that matter

My biggest issue with non-round rings so far is that they artificially inflate the power reading of most crank-based power meters. That's a non-starter for me.

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Understood on the power #'s issues.

Coming back with studies about Cadence, basically since cycling isn't force limited slow twitch fibers are plenty strong. But they also have longer contraction times and are therefore more efficient at low cadences, whereas the fast twitch fire quickly so prefer a higher cadence. http://www.umass.edu/locomotion/pdfs/job-2006.pdf http://www.edb.utexas.edu/...)%20152-157,1994.pdf

I know one of the claims Rotor and Osymmetric has made is longer endurance and a slower increase in lactic acid. My observations here could show why that might be, if it is at all. I haven't seen any studies actually look at this effect they have all looked at the power numbers.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:
Understood on the power #'s issues.

Coming back with studies about Cadence, basically since cycling isn't force limited slow twitch fibers are plenty strong. But they also have longer contraction times and are therefore more efficient at low cadences, whereas the fast twitch fire quickly so prefer a higher cadence. http://www.umass.edu/locomotion/pdfs/job-2006.pdf http://www.edb.utexas.edu/...)%20152-157,1994.pdf

I know one of the claims Rotor and Osymmetric has made is longer endurance and a slower increase in lactic acid. My observations here could show why that might be, if it is at all. I haven't seen any studies actually look at this effect they have all looked at the power numbers.


Hmmm...that first study is a mathematical model, and uses as a basis a model (Neptune, et al) that hasn't been shown to be accurate "in the field" (as far as I know) since it ass-u-me-s a constant ankle trajectory (which it's not). To quote Jim Martin "All the theory and modeling in the world will not suppress the way people actually pedal." ;-)

....and the second study just states that if you've got more type 1 fibers, then you're going to be better at endurance sports. I guess I'm not seeing how that second one applies.

I don't think you're understanding what I was getting at previously. Due to the redundant degrees of freedom in the leg mechanism, you have a MUCH greater ability to modify your upper leg muscle shortening speeds and angular joint velocities (the mechanism by which non-round rings are speculated to "work") just by flexing your ankle joint slightly differently than you could possibly do with any reasonable ring ovality. So, if a different joint velocity was more efficient (or even just "preferred"), wouldn't your body have figured out how to move that way already? In other words, that's what the "getting used to" part of switching up the rings entails...it's your body "figuring out" how to keep those upper leg joint velocities at your preferred level by changing up the lower leg movement. This is why one can lower a rider's seat by up to 6cm with no change in the maximum hip and knee angles (per Jim Martin). All of the slop is taken up in the ankle joint.

Basically, if that is true, then going to non-round rings is self-defeating. It's amazing how our bodies can figure out the "best way" when left to their own devices ;-)

http://bikeblather.blogspot.com/
Last edited by: Tom A.: Nov 19, 12 9:40
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:

Basically, if that is true, then going to non-round rings is self-defeating. It's amazing how our bodies can figure out the "best way" when left to their own devices ;-) Or, to quote Jim Martin "All the theory and modeling in the world will not suppress the way people actually pedal." ;-)

Those were the studies that were shown to me and I didn't have enough knowledge to say that my understanding was right and the studies weren't.

The knee and ankle angles stuff makes sense to me, and I wouldn't call it self defeating. It still intimidates, every group ride I've been on since I've got them despite not being any faster: "Man those oval rings really make a difference don't they? You're really cooking it today." If the competition thinks you are faster then they definitely won't be able to keep up, it's all mental!

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
joroshiba wrote:
Tom A. wrote:

Basically, if that is true, then going to non-round rings is self-defeating. It's amazing how our bodies can figure out the "best way" when left to their own devices ;-) Or, to quote Jim Martin "All the theory and modeling in the world will not suppress the way people actually pedal." ;-)

Those were the studies that were shown to me and I didn't have enough knowledge to say that my understanding was right and the studies weren't.

The knee and ankle angles stuff makes sense to me, and I wouldn't call it self defeating. It still intimidates, every group ride I've been on since I've got them despite not being any faster: "Man those oval rings really make a difference don't they? You're really cooking it today." If the competition thinks you are faster then they definitely won't be able to keep up, it's all mental!


I found this on the subject at hand today which appears to confirm that non-round rings don't change the activation of the "driving" muscles:

Adaptation of muscle coordination to altered task
mechanics during steady-state cycling

http://www.me.utexas.edu/...Papers/job33(2b).pdf

"It is also interesting to note that all the muscle
coordination adaptation occurred in the transition
muscles, and not the power muscles. These results suggest
that the transition muscles play an important role in
adapting to changing pedaling conditions and "fine-tuning
muscle coordination while the functional role of the
power producing muscles is more elementary and governed
by the task mechanics."


I also found it interesting they observed that the adaptation, even with a fairly large ovality ring, occurred quickly (within 10-20 pedal strokes), which matches what I've felt when riding around and switching back and forth between a round and non-round ring.

I'm gradually coming to the conclusion that a better name for these things would be "Placebo Rings"... :-/


http://bikeblather.blogspot.com/

Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
joroshiba wrote:
Tom A. wrote:

Basically, if that is true, then going to non-round rings is self-defeating. It's amazing how our bodies can figure out the "best way" when left to their own devices ;-) Or, to quote Jim Martin "All the theory and modeling in the world will not suppress the way people actually pedal." ;-)

Those were the studies that were shown to me and I didn't have enough knowledge to say that my understanding was right and the studies weren't.

The knee and ankle angles stuff makes sense to me, and I wouldn't call it self defeating. It still intimidates, every group ride I've been on since I've got them despite not being any faster: "Man those oval rings really make a difference don't they? You're really cooking it today." If the competition thinks you are faster then they definitely won't be able to keep up, it's all mental!


I found this on the subject at hand today which appears to confirm that non-round rings don't change the activation of the "driving" muscles:


Adaptation of muscle coordination to altered task
mechanics during steady-state cycling

http://www.me.utexas.edu/...Papers/job33(2b).pdf

"It is also interesting to note that all the muscle
coordination adaptation occurred in the transition
muscles, and not the power muscles. These results suggest
that the transition muscles play an important role in
adapting to changing pedaling conditions and "fine-tuning
muscle coordination while the functional role of the
power producing muscles is more elementary and governed
by the task mechanics."


I also found it interesting they observed that the adaptation, even with a fairly large ovality ring, occurred quickly (within 10-20 pedal strokes), which matches what I've felt when riding around and switching back and forth between a round and non-round ring.

I'm gradually coming to the conclusion that a better name for these things would be "Placebo Rings"... :-/


Nice find. I note that they also show decreased power applied at the dead spot , and increased at 90 degrees though. (Figure 3) It appears to be in equal proportions which makes sense, essentially it is still a 53t chainring turning at a certain number of rpm. However if the power you can apply at the "dead spot" that was a limiter (as might be the case in lower inertial states such as riding a trainer or climbing a mountain?), then I could see how overall power could go up. Based on this figure it certainly does one thing they claim it does, increase power in the "power phase" and decrease it in the "dead spot." From my understanding of the analysis they are examining to offset and onset of muscle use to see if the total area of use is changed, not how much force is applied in that spot. Given the very nature of the motion of the leg still being the same I cannot see how anyone would really expect this to change very much. I could be mistaken as I really don't know much about biomechanics and my limited understanding of it comes from trying to interpret articles such as these, and having more knowledgeable people correct me.



---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Interesting topic,

I purchased q-rings in the summer but due to a busy race season and testing season I did not have achance to test them properly.

Having said that I have the following n=2 observations from myself and my gf.

Annectotally they appear to work better for mashers (more peaks and valleys throughout the pedalstroke) like me an my gf.

Love em out of the saddle!

If there are power measurement issues regarding quark etc due to infered as opposed to direct measurement then I would say that you have to look for the best measurement which in this case should be tested as far away from the crank as possible.

Ideally in an erg setting measuring both mechanical out put and metabolic power.
Quote Reply
Re: Doval non-round ring's [mauricemaher] [ In reply to ]
Quote | Reply
mauricemaher wrote:
If there are power measurement issues regarding quark etc due to infered as opposed to direct measurement then I would say that you have to look for the best measurement which in this case should be tested as far away from the crank as possible.

The issue with the Quarq along with the SRM is that they both use a power calculation algorithm that assumes constant angular velocity throughout a pedal stroke, which the non-round rings change. Basically, the torque is being multiplied against a rotational velocity (the average) that is higher than the actual crank velocity while the torque is being applied. Thus, they over-read.

mauricemaher wrote:
Ideally in an erg setting measuring both mechanical out put and metabolic power.

Been there...done that, both indoors as compared to a LeMond PowerPilot and out of doors in comparison to a PT. The inflation is real.
http://forum.slowtwitch.com/...ic%20lemond;#4201113

http://forum.slowtwitch.com/...rch_string=;#4274299

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
mauricemaher wrote:

If there are power measurement issues regarding quark etc due to infered as opposed to direct measurement then I would say that you have to look for the best measurement which in this case should be tested as far away from the crank as possible.


The issue with the Quarq along with the SRM is that they both use a power calculation algorithm that assumes constant angular velocity throughout a pedal stroke, which the non-round rings change. Basically, the torque is being multiplied against a rotational velocity (the average) that is higher than the actual crank velocity while the torque is being applied. Thus, they over-read.

mauricemaher wrote:

Ideally in an erg setting measuring both mechanical out put and metabolic power.


Been there...done that, both indoors as compared to a LeMond PowerPilot and out of doors in comparison to a PT. The inflation is real.
http://forum.slowtwitch.com/...ic%20lemond;#4201113

Not discounting what you did in erg mode, my point is that analysis of inputs i.e: metabolic power formation (ie: RER, VE, HR FE02 etc..)

is critical to analyzing the benefit of these rings vs standard, I am still on the fence regarding these rings my only opinion is that as a natural "masher" and out of the saddle climber I like 'em!

Will likely do my own analysis to back up my feeling.

One thing I would find interesting is if anyone actually has any data as to how much pedal speed varies throughout the pedal stroke, re round vs non round?

Data in M/S at angles?

Any data? I am interested because not only is this important to our discussion, but is important to other topics re cadence/force/crank length etc.

http://forum.slowtwitch.com/...rch_string=;#4274299
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
i love the idea of oval chainrings but feel like there are so many grey areas.
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
isnt' actually the optimum position different from what you describe?

Quoting from noncircularchainring.be

Quote:
In case the crank is optimal oriented and the major axis of the non-circular
chainring is vertical then we see the crank arm roughly perpendicular on
the seat tube direction (“rule of thumb”).
Quote Reply
Re: Doval non-round ring's [Rob81] [ In reply to ]
Quote | Reply
Rob81 wrote:
isnt' actually the optimum position different from what you describe?

Quoting from noncircularchainring.be

Quote:
In case the crank is optimal oriented and the major axis of the non-circular
chainring is vertical then we see the crank arm roughly perpendicular on
the seat tube direction (“rule of thumb”).

You may be right...I'll have to look at that...I've found it confusing that in their diagrams they are looking at the chainring from the NDS :-/

Looks like I'm going to have to retest some stuff if that's the case. Doh!

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Question,

if you rotated the rings 90 degrees, say in the "wrong" position like the old bio-pace do you think you would see a "negative" inflation factor on the quarks.

(like a 56 gear at TDC and BDC, and a 51 gear at 90 degrees)

I guess it depends on foot speed through out the pedal stroke and if its affected the same but at opposite points.

Might not be the best idea for the knees, just curious as I was looking at a quark but may make other choices.
Quote Reply
Re: Doval non-round ring's [mauricemaher] [ In reply to ]
Quote | Reply
mauricemaher wrote:
Question,

if you rotated the rings 90 degrees, say in the "wrong" position like the old bio-pace do you think you would see a "negative" inflation factor on the quarks.

(like a 56 gear at TDC and BDC, and a 51 gear at 90 degrees)

I guess it depends on foot speed through out the pedal stroke and if its affected the same but at opposite points.
Yes, logically that would result in the power being under-reported since the average rotational velocity would be actually lower than the rotational velocity occuring during the highest torque output of the pedal cycle.

mauricemaher wrote:
Might not be the best idea for the knees, just curious as I was looking at a quark but may make other choices.

Hmmm...if it was a choice between non-round rings and a Quarq, I think I have a feeling which way I'd lean... ;-)

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
this should be the "optimal" orientation based on their mathematical model, it'd make sense because it accounts 1)the fact that vastus lateralis is more activated compared to the default, "max inertia" position + maximal hamstring activation, which is the higher end torque phase and 2) it's the phase of maximal rate/increase of torque and not just the resulting maximal final (with a cranck at ~108°-110° or ~18-20° under horizontal crank compared to ground).

Last edited by: Rob81: Nov 22, 12 0:10
Quote Reply
Re: Doval non-round ring's [Rob81] [ In reply to ]
Quote | Reply
Correct but with a rotor even a rotor xl you will probably see little to no power delta.
Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
right, it's just an example
as it's also what I've now (togheter with Ogival and Stronglight installed on another bike) while waiting for Doval and O'symetric to arrive, it's quite a long way from SK and USA to Italy :)
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
According to this interview/piece...'I asked an SRM engineer about the possibility of this and he tells me that it would be impossible for the osymetric chainrings to affect the readings of an SRM powermeter.'

http://www.cyclingtips.com.au/...-gimmick-or-miracle/

Thought it was a good article. Found the bit about Wiggins and co switching to round rings to train on a week before a race to get a 'turbo boost' then switching back the day before the start interesting.
Last edited by: Magwister: Nov 22, 12 8:25
Quote Reply
Re: Doval non-round ring's [Magwister] [ In reply to ]
Quote | Reply
Magwister wrote:
According to this interview/piece...'I asked an SRM engineer about the possibility of this and he tells me that it would be impossible for the osymetric chainrings to affect the readings of an SRM powermeter.'

Yeah...I've seen that comment. I hate to say it, but the author of that article either talked to the wrong engineer at SRM, or the engineer doesn't understand the issue...or both.

This was all "sussed out" way back in 2006 on the Wattage list in a thread started by Jens Heycke were he reported observing a difference in SRM vs. PT reported power when using round rings, Rotor rings, and Osymetrics when riding outside:

https://groups.google.com/...rBUKY20s0/discussion

Ironically, even back then, the SRM "expert" on the thread (Jason Yanota) didn't seem to quite grasp the issue...

Magwister wrote:
Thought it was a good article

Meh...

Magwister wrote:
Found the bit about Wiggins and co switching to round rings to train on a week before a race to get a 'turbo boost' then switching back the day before the start interesting.

Placebo is a powerful thing!

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom,

I'm sure this was answered somewhere so sorry for asking, but do you consider a Powertap an accurate tool to measure any potentiel improvement (if there is one) with non round chainrings as opposed to round.

I've just ordered a new Powercranks (let's not start the powercranks debate... please guys) with the Dual mode (which I don't normally use), I'm considering testing different things with it :
- install two 50T rings, one round and then one Qring which I might change for an Osymetric after that, look at power / heart rate / feel of exhaustion.
- change crank lenght with 5mm steps, starting at 165mm (my actual crank lenght on TT bike) and then removing 5mm and increase saddle height 5mm (don't think I'll actually change bar height for the test) and so on. I can probably do thing also with the two different rings on.

I have a Powertap G3 on the back of my 596 with Powercranks so there is probably a chance I can test both separately but also at the same time, I read your suggestion that shortening the crank arms might actually provide a similar feeling/"benefit" (again if any) as riding the Osymetric ring.

I'm happy to discuss that with you and maybe the testing I can do can complement what you are doing on your side. But first I need to make sure the Powertap can provide accurate results, because differences we are trying to measure are so small that if the non round ring tend to provide non-accurate results even on Powertap then there is no point in trying to measure anything (I'll still work on the crank lenght thing though as it is what I'm most interested in right now).

Thanks Tom for any help you can provide.
Quote Reply
Re: Doval non-round ring's [pyf] [ In reply to ]
Quote | Reply
pyf wrote:
Tom,

I'm sure this was answered somewhere so sorry for asking, but do you consider a Powertap an accurate tool to measure any potentiel improvement (if there is one) with non round chainrings as opposed to round.

Yes. The PT uses a different calculation algorithm (time based vs. "event" based) and so wouldn't be susceptible to the "inflation factor".

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Rob81] [ In reply to ]
Quote | Reply
any updates on the doval?
Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
DarkSpeedWorks wrote:
rruff wrote:
Osymetrics have been used very successfully by pros lately... I wouldn't call that "dead in the water".


If osymetrics work, they would work far, far better for way more athletes if they had angular adjustment capability. A fixed ring forces you to take a gamble that the design will work ok with your set up. Kind of an iffy gamble.

You are making very strong statements. What do you base them on? Impressions or studies? I'm always wary of absolute statements based on subjective impressions.

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
Quote Reply
Re: Doval non-round ring's [jever98] [ In reply to ]
Quote | Reply
jever98 wrote:
You are making very strong statements. What do you base them on?

You are right to be skeptical of absolute statements. And I didn't do a good job of it, but I was trying to make a qualified statement. IF non-round rings improve efficiency or sustained power, then angular adjustment is really essential.

So what do I base that on? Basic physics and geometry. Knowledge of how significantly bike fits vary among individuals. Knowledge of how much frame geometry, especially in the rear triangle, varies among brands. An understanding of how forces are applied on chain-driven mechanisms. The bottom line is that the range of angles between your hip joint and the chainline is huge. And the angle is even affected a lot by many things folks don't consider, like even something as seemingly mundane as your gear choice.

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Interesting/intriguing conversation Tom and others.

A good case has been made about the artifactual inflation of the power numbers reported by crank based PM's. A display of high (or low, take your pick) power numbers during a race/workout has undoubtedly psychological effects. Some might be good, others might be bad. That's a little bit like a "you can do it!" or a "you're in way over your head, buddy!" bouncing inside the head. No doubt. Maybe that's were the value of the Osymmetric/Oval rings resides for some.

Now, another way of looking at the observed inflation would be as the proof that the rings DO change pedal velocity during the 360 rotation. The greater the inflation the greater the change in angular velocities. In my mind then, the question becomes: what are the metabolic/physiological consequences???

If the above is making any sense, perhaps should we look first at pedaling regimes (hill climb, TT, sprinting etc...) were the inflation is the greatest and then try to tease out if the outcome (ie, achieved speed/duration ) is favorable, no?

Quote:
Been there...done that, both indoors as compared to a LeMond PowerPilot and out of doors in comparison to a PT. The inflation is real.
http://forum.slowtwitch.com/...ic%20lemond;#4201113

http://forum.slowtwitch.com/...rch_string=;#4274299

Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
DarkSpeedWorks wrote:
jever98 wrote:

You are making very strong statements. What do you base them on?


You are right to be skeptical of absolute statements. And I didn't do a good job of it, but I was trying to make a qualified statement. IF non-round rings improve efficiency or sustained power, then angular adjustment is really essential.

So what do I base that on? Basic physics and geometry. Knowledge of how significantly bike fits vary among individuals. Knowledge of how much frame geometry, especially in the rear triangle, varies among brands. An understanding of how forces are applied on chain-driven mechanisms. The bottom line is that the range of angles between your hip joint and the chainline is huge. And the angle is even affected a lot by many things folks don't consider, like even something as seemingly mundane as your gear choice.

Well, the point that angular adjustment is really essential is something I am not fully on board with. You seem to be assuming that differences in the angle of the oval are really important. When I compare my road vs TT bike position I am rotated forward around the bottom bracket, but my hip angle seems to stay roughly the same. Neither Qs nor Osymetrics have felt much different between my road and TT bike, despite the different positions. It would be fairest to do a systematic comparison between the different angle options on the Rotors before making a strong recommendation. So before saying that Q-Rings are a "killer app" because of the angular adjustment, I think one would really need to get some info to check it.

As context (and so this is not just about the angle question): I have been using Round rings, Q rings, and Osymetrics in the last two years. At the moment I have Osymetrics on my TT bike and Q rings on my road bike. I have personally not found any differences between round and ovalized rings in absolute power on, say, 20min or 5min tests with my PM, nor on HR to power relationships. However, I have noticed that the muscle groups seem to get used differently and I like the feel of ovalized rings. To me osymetric feel nicer because they are more ovalized, but I don't like the shifting quality. Also like ovalized rings a lot for out of saddle climbing - seems to work really well.

Cheers
Jever

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
Quote Reply
Re: Doval non-round ring's [jever98] [ In reply to ]
Quote | Reply
jever98 wrote:
Well, the point that angular adjustment is really essential is something I am not fully on board with. You seem to be assuming that differences in the angle of the oval are really important.


Sure, I follow you, but I'm not certain that it's important. More that I'm saying that if a non-circular chainring is important, then it logically follows that angular adjustment is important. It's kind of an 'if a=b and b=c, then a=c' type of argument. You kind of have to think about why the chainring shape is important in the first place. Why does the differing radius make a difference? Because it changes the mechanical advantage that the rider has on the chain. And that increased (and decreased) mechanical advantage depends 100% on where the pushing is coming from (i.e., where the rider's legs are located) and the location of the item being pulled (i.e., the chain). The effectiveness (or lack thereof) of non-round chainrings depends wholly on the angular relationship between the two.

Greg @ dsw

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Last edited by: DarkSpeedWorks: Dec 7, 12 13:06
Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
The angle of the chain doesn't make a difference, as far as I can tell, other than that it changes slightly where the chain contacts the chain ring, and therefore where on the ovalization it is. However, by eyeballing it on my bike it looks like the difference between the biggest and smallest sprocket makes a small difference in terms of contact point.

Secondly the angle at which the oval sits: adjusting it is only important if it was "in the wrong orientation" for what you are doing. If it's in the right place then there is no need to change it. Let's assume the most frequent orientation (position 3 on a Q ring) is "correct" for most road cyclists. You would only want to change that if your pedaling mechanics fundamentally change. The pedaling mechanics would only change if the relative position of your joints relative would change. However, if you just rotate your pedaling motion around the BB, nothing really changes.

---
power2max
http://www.power2max.com/northamerica
official power meter of Movistar Team
Quote Reply
Re: Doval non-round ring's [DarkSpeedWorks] [ In reply to ]
Quote | Reply
DarkSpeedWorks wrote:
jever98 wrote:
Well, the point that angular adjustment is really essential is something I am not fully on board with. You seem to be assuming that differences in the angle of the oval are really important.


Sure, I follow you, but I'm not certain that it's important. More that I'm saying that if a non-circular chainring is important, then it logically follows that angular adjustment is important. It's kind of an 'if a=b and b=c, then a=c' type of argument. You kind of have to think about why the chainring shape is important in the first place. Why does the differing radius make a difference? Because it changes the mechanical advantage that the rider has on the chain. And that increased (and decreased) mechanical advantage depends 100% on where the pushing is coming from (i.e., where the rider's legs are located) and the location of the item being pulled (i.e., the chain). The effectiveness (or lack thereof) of non-round chainrings depends wholly on the angular relationship between the two.

Greg @ dsw

...and if it isn't important? ;-)

http://bikeblather.blogspot.com/
Quote Reply
Re: Doval non-round ring's [Tom A.] [ In reply to ]
Quote | Reply
Tom A. wrote:
...and if it isn't important? ;-)

Well, then we're just, uh, pondering our belly buttons ...

Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
DarkSpeedWorks.com.....Reviews.....Insta.....Facebook

--
Quote Reply
Re: Doval non-round ring's [ren-ge] [ In reply to ]
Quote | Reply
I've been running the Doval in its default configuration for over a month now. Still shifts very well, couldn't for the life of me tell you whether or not there was an actual improvment in power, although my average speed has gone up since then I've also started actually training. Rode them on rollers for the first time a couple days ago and was surprise that it was if anything smoother than normal.

Still need to try the "optimal" position but I've been hesitant because not sure how it will affect shifting (ramps and pin placement). I'd be interested to see what Rob finds with his power meter.

EDIT: I've decided to go ahead and bit the bullet I'll switch it to optimal position tonight. I'll let you know if I "feel" anything different.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Last edited by: joroshiba: Dec 7, 12 15:41
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Ok Doval rings set up as close to "Optimal" as I think they will get. About 50 degrees to the minor axis and 110 to the major. (I'm assuming i failed to some extent with these angles so just rounded to the nearest 10). I'll report back if anything feels either terrible or fantastic on this next ride



---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Alright rode them in the "optimal" position this AM, 2 HR tempo ride on my normal 2 hr tempo ride route. I can't say if they were really any better or worse though. It was rainy I was overdressed and it was windy. Anywho: I did notice that my glutes got a little more action and my quads and hamstrings a little less. I'm not sure whether or not this was good but I've been having some knee issues as of late and didn't have those today so it at least seemed to remove some force from those.

This configuration also took a lot longer to "adjust" to which once again I'm not sure if that is good or bad. They do most certainly feel different and when standing they feel like shit (as I largely expected seeing as the dead spot kinda moves a bit and my peak power tends to occur closer to where the easy section of this config is. I'll do at least 2 more weeks of riding on this and then I'm thinking I might switch them to where the major axis is precisely perpendicular to the crank arm.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Alright, 2 weeks on them don't like this "optimal" positioning. It feels like it hit the easy spot when I still have power to give and force starts increasing before I have power to give. Also feels like shit out of the saddle. I'm going to try halfway between the stock position and the "optimal" position. If that doesn't work out I'll go back to the stock because I liked that just fine and had multiple of my fastest times on it. I think halfway between will be close to perfect seated not sure about standing.

No real hard science here, but I noticed group rides were a tad harder with this current position and I do a regular route that is about 2 Hrs of tempo, haven't been able to hit it as fast as I did in the stock position. Nothing concrete just what I feel, but if I feel slow I am slow!

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
There just aren't enough positions to dial it in correctly. This is something rotor has figured out, not sure why other companies aren't doing the same (in terms of mounting positions). I've put about 800 miles on my Prototype 2.0 modified osy-like shape (below) with multiple mounting positions. So far I have the mounting positions narrowed to two depending on the type of riding (hilly riding more upright or flat in the drops/sitting further forward).


Planning on setting up my test rig after new years when I finish my new prototype (fixes some FD clearing issues and will be black to match). Btw this is just a hobby and more of an experiment, nothing is for sale (got a few PMs last time). These would not be ideal for most people as wrenching is a bit tricky and can sometimes require a dremel...but I have yet to drop a chain!





Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
Yeah I'm wishing it had a couple more positions about now! Is the setup it is currently in your flats or hilly chainring position?

Very interested in seeing how your testing works out. I'm very much considering scrapping the rings since I will be dealing with inflation factor if I put them on the Quarq I will be purchasing in about a month, and have seen no real improvements yet. (not saying they aren't there, could be a small advantage) Plus the issue with different positions. I'm thinking that if you were fixated in a TT position they might be good, but for road cycling and racing circular seems to be the best compromise for all situations. I'll give them another month though.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Last edited by: joroshiba: Dec 20, 12 10:15
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Right now it's in a normal riding position configuration. It's great for riding on the hoods. On a TT bike or a flat road race, Id rotate one position counterclockwise. I'll start posting power data when I fix my powertap...
Quote Reply
Re: Doval non-round ring's [Mrcooper] [ In reply to ]
Quote | Reply
Interesting: I didn't like the position similar to that one right there at all. Felt like I had a lot more push time left before it moved towards the "deadspot" section, and felt as though the onset of force was far too soon. I natrually can only make large adjustments but I've now got it setup so that the minor axis is vertical when the crank arm is inline with the seat tube and that feels pretty good so far. Based on feel I'm trying to optimize the location of the easy section not the power section because that seems to make the biggest difference.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Any updates on the feel and perceived gains from the rings? Worthwhile trying out or should I save a little more for some rotor's?

Thanks
Andrew
Quote Reply
Re: Doval non-round ring's [Dad2twins] [ In reply to ]
Quote | Reply
I perceived some gain upon putting the smallest section directly under the crankarm, as well as the default position. I am not using them any more though, this is more a non circular chainring issue though. When setup optimally for standing, they felt terrible when seated when set up optimally for being seated they felt terrible standing. Being a roadie and a mountain goat I do a fair bit of both, I decided a circular chainring offered me the best of all worlds.

---------------------
Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access
Quote Reply
Re: Doval non-round ring's [joroshiba] [ In reply to ]
Quote | Reply
Interestingly there are now new chainrings from Doval which, like Rotor, have more OCP settings. I tried q rings on my tri bike and o symetrics on my road bike. The os seem to give me more power and also a slightly lower cadence. Since I have a retul move fit bike with a computrainer on it I see worse spinscan values then with round rings. And not only for myself, but with almost any other fit client. However, when I rotated the os into a non advised position I scored great spinscan values. This puzzled me at that time and I stopped testing to clarify this with Rotor and Osymetric. No answer yet, but reading the rotor website you expect better spinscan values with non round rings.
But on the retul move fit bike changing the seat angle from road to tri with an os doesn't seem to influence the spinscan values. So that questions the use of the OCP settings. But I must admit that on the real road on my tri bike I prefer OCP 4 over 3 on the rotor.
I just received the QXL. The weather improved at my place so Incan start riding outdoors again. I will order a new Doval as well.

Anyone an idea why spinscan values seem to be lower with the qr or the os in adviced position?

Owner at TRIPRO, The Netherlands
Quote Reply
Re: Doval non-round ring's [tri-run] [ In reply to ]
Quote | Reply
Hi Tri-run,

Pay no attention to spin scan values. They are unrelated to performance, perhaps counter-related if anything.

The only way to score well is to reduce your power until your down stroke is as weak as your up stroke. But to go fast you must push hard on the down stroke. QED.

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
Quote Reply
Post deleted by JanSnorway [ In reply to ]
Re: Doval non-round ring's [damon_rinard] [ In reply to ]
Quote | Reply
hi all, is this chaining installed correctly?



https://plus.google.com/...02492928415224030904
Quote Reply